From a4216351c0299765e0330415f03bd5bfabcac9f9 Mon Sep 17 00:00:00 2001
From: Stefan Knoblich <stkn@openisdn.net>
Date: Fri, 24 Aug 2012 00:15:35 +0200
Subject: [PATCH] ftmod_libpri: Implement channel hunting in NT-mode.
Hunt for a free channel for incoming calls that do not
preselect a channel (pevent->ring.channel == -1).
Verify the preselected channel for calls that do specify a channel
and in case the channel is already taken, hunt for a free one,
or abort with an error message (if the preselection was exclusive).
TE-mode channel selection is the same as before
(there's still room for improvement, though, but i'll save that for later).
The MSN/DDI filter code is moved into the TE-mode section (only useful there).
The duplicate ring detection had to be reworked. We now store the
call reference (CRV) in caller_data->call_reference of the selected channel
and do a CRV -> channel look up with find_channel_by_cref()
at the top of on_ring().
NOTE: This is only lightly tested (NT/TE mode), i'd either have to
write a lot of custom code to check it toroughly or the need for
a scriptable ISDN stack...
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>
---
.../src/ftmod/ftmod_libpri/ftmod_libpri.c | 256 ++++++++++++++----
1 file changed, 200 insertions(+), 56 deletions(-)
diff --git a/libs/freetdm/src/ftmod/ftmod_libpri/ftmod_libpri.c b/libs/freetdm/src/ftmod/ftmod_libpri/ftmod_libpri.c
index 0b3a999ee1..32a7e09b83 100644
--- a/libs/freetdm/src/ftmod/ftmod_libpri/ftmod_libpri.c
+++ b/libs/freetdm/src/ftmod/ftmod_libpri/ftmod_libpri.c
@@ -1538,6 +1538,107 @@ out:
return 0;
}
+
+/**
+ * Look up FreeTDM channel by call reference value
+ * \param[in] span Span object
+ * \param[in] crv CRV to search for
+ * \return Channel on success, NULL otherwise
+ */
+static ftdm_channel_t *find_channel_by_cref(ftdm_span_t *span, const int cref)
+{
+ ftdm_iterator_t *iter = NULL;
+ ftdm_channel_t *chan = NULL;
+
+ if (!span || cref <= 0)
+ return NULL;
+
+ ftdm_mutex_lock(span->mutex);
+
+ /* Iterate over all channels on this span */
+ for (iter = ftdm_span_get_chan_iterator(span, NULL); iter; iter = ftdm_iterator_next(iter)) {
+ ftdm_channel_t *cur = ftdm_iterator_current(iter);
+ ftdm_caller_data_t *caller_data = NULL;
+
+ if (ftdm_channel_get_type(cur) != FTDM_CHAN_TYPE_B)
+ continue;
+
+ caller_data = ftdm_channel_get_caller_data(cur);
+
+ if (caller_data->call_reference == cref) {
+ chan = cur;
+ break;
+ }
+ }
+
+ ftdm_iterator_free(iter);
+ ftdm_mutex_unlock(span->mutex);
+ return chan;
+}
+
+
+/**
+ * Hunt for free channel (NT-mode only)
+ * \param[in] span Span to hunt on
+ * \param[in] hint Channel ID hint (preferred by remote end)
+ * \param[in] excl Is the hint exclusive (or preferred)?
+ * \param[out] chan Selected channel
+ * \retval FTDM_SUCCESS A free channel has been found
+ * \retval FTDM_FAIL No free channels could be found on the span
+ * \retval FTDM_EBUSY The channel indicated in the exclusive hint is already in use
+ */
+static ftdm_status_t hunt_channel(ftdm_span_t *span, const int hint, const ftdm_bool_t excl, ftdm_channel_t **chan)
+{
+ ftdm_iterator_t *iter = NULL;
+ ftdm_channel_t *tmp = NULL;
+ int ret = FTDM_FAIL;
+
+ /* lock span */
+ ftdm_mutex_lock(span->mutex);
+
+ /* Check hint */
+ if (hint > 0) {
+ tmp = ftdm_span_get_channel(span, hint);
+ if (!tmp) {
+ ftdm_log(FTDM_LOG_NOTICE, "Invalid channel hint '%d' given (out of bounds)\n", hint);
+ }
+ else if (!ftdm_test_flag(tmp, FTDM_CHANNEL_INUSE) && ftdm_channel_get_type(tmp) == FTDM_CHAN_TYPE_B) {
+ ftdm_log(FTDM_LOG_DEBUG, "Using channel '%d' from hint\n", ftdm_channel_get_id(tmp));
+ ftdm_channel_use(tmp);
+ ret = FTDM_SUCCESS;
+ *chan = tmp;
+ goto out;
+ }
+ else if (excl) {
+ ftdm_log(FTDM_LOG_NOTICE, "Channel '%d' in exclusive hint is not available\n",
+ ftdm_channel_get_id(tmp));
+ ret = FTDM_EBUSY;
+ goto out;
+ }
+ }
+
+ /* Iterate over all channels on this span */
+ for (iter = ftdm_span_get_chan_iterator(span, NULL); iter; iter = ftdm_iterator_next(iter)) {
+ tmp = ftdm_iterator_current(iter);
+
+ if (ftdm_channel_get_type(tmp) != FTDM_CHAN_TYPE_B)
+ continue;
+
+ if (!ftdm_test_flag(tmp, FTDM_CHANNEL_INUSE)) {
+ ftdm_channel_use(tmp);
+ ret = FTDM_SUCCESS;
+ *chan = tmp;
+ break;
+ }
+ }
+
+ ftdm_iterator_free(iter);
+out:
+ ftdm_mutex_unlock(span->mutex);
+ return ret;
+}
+
+
/**
* \brief Handler for libpri ring event
* \param spri Pri wrapper structure (libpri, span, dchan)
@@ -1553,76 +1654,96 @@ static int on_ring(lpwrap_pri_t *spri, lpwrap_pri_event_t event_type, pri_event
ftdm_caller_data_t *caller_data = NULL;
int ret = 0;
- if (pevent->ring.channel == -1) {
+ /*
+ * Check if call has an associated channel (duplicate ring event)
+ */
+ if ((chan = find_channel_by_cref(span, pevent->ring.cref))) {
+ ftdm_log_chan_msg(chan, FTDM_LOG_NOTICE, "-- Duplicate ring received (ignored)\n");
+ return ret;
+ }
+
+ if (isdn_data->mode == PRI_NETWORK) {
+ /*
+ * Always hunt for a free channel in NT-mode,
+ * but use the pre-selected one as hint
+ */
+ switch (hunt_channel(span, pevent->ring.channel, !pevent->ring.flexible, &chan)) {
+ case FTDM_SUCCESS: /* OK channel found */
+ break;
+ case FTDM_EBUSY: /* Exclusive channel hint is not available */
+ ftdm_log(FTDM_LOG_ERROR, "-- New call without channel on span '%s' [NOTE: Initial SETUP w/o channel selection is not supported by FreeTDM]\n",
+ ftdm_span_get_name(span));
+ pri_hangup(spri->pri, pevent->ring.call, PRI_CAUSE_CHANNEL_UNACCEPTABLE);
+ return ret;
+ default:
+ ftdm_log(FTDM_LOG_ERROR, "-- New call without channel on span '%s' [NOTE: Initial SETUP w/o channel selection is not supported by FreeTDM]\n",
+ ftdm_span_get_name(span));
+ pri_hangup(spri->pri, pevent->ring.call, PRI_CAUSE_NORMAL_CIRCUIT_CONGESTION);
+ return ret;
+ }
+
+ ftdm_channel_lock(chan);
+
+ } else if (pevent->ring.channel == -1) {
+ /*
+ * TE-mode incoming call without channel selection (not supported)
+ */
ftdm_log(FTDM_LOG_ERROR, "-- New call without channel on span '%s' [NOTE: Initial SETUP w/o channel selection is not supported by FreeTDM]\n",
ftdm_span_get_name(span));
pri_destroycall(spri->pri, pevent->ring.call);
return ret;
- }
-
- chan = ftdm_span_get_channel(span, pevent->ring.channel);
- if (!chan) {
- ftdm_log(FTDM_LOG_ERROR, "-- Unable to get channel %d:%d\n",
- ftdm_span_get_id(span), pevent->ring.channel);
- pri_hangup(spri->pri, pevent->ring.call, PRI_CAUSE_DESTINATION_OUT_OF_ORDER);
- return ret;
- }
-
- /* check MSN filter */
- if (!msn_filter_match(isdn_data, pevent->ring.callednum)) {
- ftdm_log(FTDM_LOG_INFO, "-- MSN filter not matching incoming DNIS '%s', ignoring call\n",
- pevent->ring.callednum);
- pri_destroycall(spri->pri, pevent->ring.call);
- return ret;
- }
-
- ftdm_channel_lock(chan);
-
- if (chan->call_data) {
- /* we could drop the incoming call, but most likely the pointer is just a ghost of the past,
- * this check is just to detect potentially unreleased pointers */
- ftdm_log_chan(chan, FTDM_LOG_ERROR, "channel already has call %p!\n", chan->call_data);
- chan->call_data = NULL;
- }
-
- if (ftdm_channel_get_state(chan) != FTDM_CHANNEL_STATE_DOWN || ftdm_test_flag(chan, FTDM_CHANNEL_INUSE)) {
- ftdm_log(FTDM_LOG_WARNING, "-- Duplicate Ring on channel %d:%d (ignored)\n", ftdm_span_get_id(span), pevent->ring.channel);
- goto done;
- }
-
- if ((pevent->ring.progressmask & PRI_PROG_INBAND_AVAILABLE)) {
- /* Open channel if inband information is available */
- ftdm_log(FTDM_LOG_DEBUG, "-- In-band information available, opening B-Channel %d:%d\n",
- ftdm_channel_get_span_id(chan),
- ftdm_channel_get_id(chan));
-
- if (!ftdm_test_flag(chan, FTDM_CHANNEL_OPEN) && ftdm_channel_open_chan(chan) != FTDM_SUCCESS) {
-// ftdm_caller_data_t *caller_data = ftdm_channel_get_caller_data(chan);
-
- ftdm_log(FTDM_LOG_WARNING, "-- Error opening channel %d:%d (ignored)\n",
- ftdm_channel_get_span_id(chan),
- ftdm_channel_get_id(chan));
-
-// caller_data->hangup_cause = FTDM_CAUSE_DESTINATION_OUT_OF_ORDER;
-// ftdm_set_state_locked(chan, FTDM_CHANNEL_STATE_TERMINATING);
-// goto done;
- }
} else {
- /* Reserve channel, don't open it yet */
- if (ftdm_channel_use(chan) != FTDM_SUCCESS) {
- ftdm_log(FTDM_LOG_WARNING, "-- Error reserving channel %d:%d (ignored)\n",
+ /*
+ * TE-mode, check MSN filter, ignore calls that aren't for this PTMP terminal
+ */
+ if (!msn_filter_match(isdn_data, pevent->ring.callednum)) {
+ ftdm_log(FTDM_LOG_INFO, "-- MSN filter not matching incoming DNIS '%s', ignoring call\n",
+ pevent->ring.callednum);
+ pri_destroycall(spri->pri, pevent->ring.call);
+ return ret;
+ }
+
+ /*
+ * TE-mode channel selection, use whatever the NT tells us to
+ */
+ chan = ftdm_span_get_channel(span, pevent->ring.channel);
+ if (!chan) {
+ ftdm_log(FTDM_LOG_ERROR, "-- Unable to get channel %d:%d\n",
ftdm_span_get_id(span), pevent->ring.channel);
+ pri_hangup(spri->pri, pevent->ring.call, PRI_CAUSE_DESTINATION_OUT_OF_ORDER);
+ return ret;
+ }
+
+ ftdm_channel_lock(chan);
+
+ if (ftdm_channel_get_state(chan) != FTDM_CHANNEL_STATE_DOWN || ftdm_test_flag(chan, FTDM_CHANNEL_INUSE)) {
+ ftdm_log_chan_msg(chan, FTDM_LOG_ERROR, "-- Selected channel is already in use\n");
+ pri_hangup(spri->pri, pevent->ring.call, PRI_CAUSE_DESTINATION_OUT_OF_ORDER);
+ goto done;
+ }
+
+ /* Reserve channel */
+ if (ftdm_channel_use(chan) != FTDM_SUCCESS) {
+ ftdm_log_chan_msg(chan, FTDM_LOG_ERROR, "-- Error reserving channel\n");
+ pri_hangup(spri->pri, pevent->ring.call, PRI_CAUSE_DESTINATION_OUT_OF_ORDER);
goto done;
}
}
- ftdm_log(FTDM_LOG_NOTICE, "-- Ring on channel %d:%d (from %s to %s)\n", ftdm_span_get_id(span), pevent->ring.channel,
- pevent->ring.callingnum, pevent->ring.callednum);
+ if (chan->call_data) {
+ /* we could drop the incoming call, but most likely the pointer is just a ghost of the past,
+ * this check is just to detect potentially unreleased pointers */
+ ftdm_log_chan(chan, FTDM_LOG_WARNING, "Channel already has call %p!\n", chan->call_data);
+ chan->call_data = NULL;
+ }
caller_data = ftdm_channel_get_caller_data(chan);
memset(caller_data, 0, sizeof(*caller_data));
+ /* Save CRV, so we can do proper duplicate RING detection */
+ caller_data->call_reference = pevent->ring.cref;
+
ftdm_set_string(caller_data->cid_num.digits, (char *)pevent->ring.callingnum);
ftdm_set_string(caller_data->ani.digits, (char *)pevent->ring.callingani);
ftdm_set_string(caller_data->dnis.digits, (char *)pevent->ring.callednum);
@@ -1642,7 +1763,30 @@ static int on_ring(lpwrap_pri_t *spri, lpwrap_pri_event_t event_type, pri_event
/* hurr, this is valid as along as nobody releases the call */
chan->call_data = pevent->ring.call;
- /* only go to RING state if we have the complete called number (indicated via pevent->complete flag) */
+ /* Open Channel if inband information is available */
+ if ((pevent->ring.progressmask & PRI_PROG_INBAND_AVAILABLE)) {
+ /* Open channel if inband information is available */
+ ftdm_log(FTDM_LOG_DEBUG, "-- In-band information available, opening B-Channel %d:%d\n",
+ ftdm_channel_get_span_id(chan),
+ ftdm_channel_get_id(chan));
+
+ if (!ftdm_test_flag(chan, FTDM_CHANNEL_OPEN) && ftdm_channel_open_chan(chan) != FTDM_SUCCESS) {
+// ftdm_caller_data_t *caller_data = ftdm_channel_get_caller_data(chan);
+
+ ftdm_log(FTDM_LOG_WARNING, "-- Error opening channel %d:%d (ignored)\n",
+ ftdm_channel_get_span_id(chan),
+ ftdm_channel_get_id(chan));
+
+// caller_data->hangup_cause = FTDM_CAUSE_DESTINATION_OUT_OF_ORDER;
+// ftdm_set_state_locked(chan, FTDM_CHANNEL_STATE_TERMINATING);
+// goto done;
+ }
+ }
+
+ ftdm_log(FTDM_LOG_NOTICE, "-- Ring on channel %d:%d (from %s to %s)\n", ftdm_span_get_id(span), pevent->ring.channel,
+ pevent->ring.callingnum, pevent->ring.callednum);
+
+ /* Only go to RING state if we have the complete called number (indicated via pevent->complete flag) */
if (!pevent->ring.complete && (isdn_data->overlap & FTMOD_LIBPRI_OVERLAP_RECEIVE)) {
ftdm_log(FTDM_LOG_DEBUG, "RING event without complete indicator, waiting for more digits\n");
ftdm_set_state(chan, FTDM_CHANNEL_STATE_COLLECT);